Some reports on Weed

Sux!!! I gotta free my country off their web of lies, i've been sober too long... darn!!! People get a jail term of more than 1 year for taking weed where i come from. And those anti-drug campaigns here really pisses me off, set up by people who have never even tasted weed. It's like explaining rock to a 1920's nerd, hell screw up!!!
Some latest news from new scientist=>

Long-term marijuana use may fog the brain

21:00 13 March 2006

NewScientist.com news service

Andy Coghlan

Long-term users of marijuana gradually become worse at learning and remembering things, a new study suggests.
â€œIt definitely fogs your brain,â€ says Lambros Messinis, who led the study at the University Hospital of Patras in Greece.
Messinis and colleagues tested the mental abilities of 20 long-term users who had taken marijuana heavily â€“ smoking at least four joints a week â€“ for an average of 15 years. Their brains were rustier than those of 20 short-term users â€“ who had averaged seven years of use â€“ and 24 controls who had used the drug sporadically or not at all.
Long-term users performed worse in tests to measure memory, learning ability and the capacity to recall information. Asked to recall lists of 15 words that they had seen earlier, for example, the long-term users averaged seven, compared with nine recalled by short-term users and 12 by controls.
â€œLong-term users found it very difficult to learn through new information given verbally,â€ says Messinis. â€œIt's not to do with lack of attention but more the encoding process of memory.â€ Separate tests to probe attention span found that long-term users were able to pick up information immediately, without trouble.Initial ability

Although the study is retrospective â€“ that is, the subjects were not tested on their cognitive abilities before they took up marijuana â€“ the researchers are confident that the long-term users' abilities were not significantly different from the other groups from the beginning. They used a standard test to estimate the long-term users' original intellectual abilities.
Messinis gave subjects the tests at least 24 hours after they had last taken the drug, to make sure they were not still under the influence. â€œIt wasn't while they were high,â€ he says.
â€œImportantly, we don't know if it's reversible,â€ he says. To find out, he and his colleague plan to re-test the same subjects after abstinence periods of at least a month.
Nadia Solowij, at the University of Wollongong in Australia, says the new findings back previous work by her and colleagues, published in the Journal of the American Medical Association in 2002.
â€œThe authors appear to have used the same rigorous criteria for inclusion in their study and confirm that the duration of cannabis use progressively impacts upon cognitive functions,â€ she told New Scientist.
Journal reference: Neurology (vol 66, p 737)

Some dumb arse document people can write......... I use to think it is true that we start to forget more things after taking weed for a few years.. But that is purely a load of crap, it just feels that way man, totally feels that way!!!!!!!
I got ban from weed later due to moving back to my country, and have been sober for 4 years, and many a times, i got praise for great memory power, being able to recall thingss happening in detail months before..
Yes, dumb nerds, the effect of losing memory is reversible, absolutely!!! And more than that, we get better memory power after that!!!

Marijuana might cause new cell growth in the brain
22:00 13 October 2005
NewScientist.com news service
Kurt Kleiner
A synthetic chemical similar to the active ingredient in marijuana makes new cells grow in rat brains. What is more, in rats this cell growth appears to be linked with reducing anxiety and depression. The results suggest that marijuana, or its derivatives, could actually be good for the brain.
In mammals, new nerve cells are constantly being produced in a part of the brain called the hippocampus, which is associated with learning, memory, anxiety and depression. Other recreational drugs, such as alcohol, nicotine and cocaine, have been shown to suppress this new growth. Xia Zhang of the University of Saskatchewan in Saskatoon, Canada, and colleagues decided to see what effects a synthetic cannabinoid called HU210 had on rats' brains.
They found that giving rats high doses of HU210 twice a day for 10 days increased the rate of nerve cell formation, or neurogenesis, in the hippocampus by about 40%. Just like Prozac?

A previous study showed that the antidepressant fluoxetine (Prozac) also increases new cell growth, and the results indicated that it was this cell growth that caused Prozac's anti-anxiety effect. Zhang wondered whether this was also the case for the cannabinoid, and so he tested the rats for behavioural changes.
When the rats who had received the cannabinoid were placed under stress, they showed fewer signs of anxiety and depression than rats who had not had the treatment. When neurogenesis was halted in these rats using X-rays, this effect disappeared, indicating that the new cell growth might be responsible for the behavioural changes.
In another study, Barry Jacobs, a neuroscientist at Princeton University, gave mice the natural cannabinoid found in marijuana, THC (D9-tetrahydrocannabinol)). But he says he detected no neurogenesis, no matter what dose he gave or the length of time he gave it for. He will present his results at the Society for Neuroscience meeting in Washington DC in November.
Jacobs says it could be that HU210 and THC do not have the same effect on cell growth. It could also be the case that cannabinoids behave differently in different rodent species - which leaves open the question of how they behave in humans.
Zhang says more research is needed before it is clear whether cannabinoids could some day be used to treat depression in humans.
Journal reference: Journal of Clinical Investigation (DOI:10.1172/JCI25509)

To me, it's like farming, like growing plants, you need to trim the sides so that new leaves can grow. I think that is what weed does to our brain, it makes us forget things initially, like trimming our brain, then it grows new brain cells in, making our brain stronger and wiser.
Darn nerds will always complain on everything that doesn't follow the line they walk on!!!

Old School

I believe that long term use of weed does cloud some brain functions, such as memory. However, as you said, i think that weed opens up the brain in other ways.

If you want to drastically increase your short-term memory, all you really need to do is grab a $10 memory technique book. This way you can remember the #'s on the back of a deck of cards if that's important to you...lol. If your learning ability is improtant to you (it is to me) i say keep a good diet and continuously challenge your brain-- you'll probably do better than those sober people in the tests, regardless if you smoke everyday. Basically just dont get high and watch hours of mind numbing TV all the time

edit: posting on GC is a hell of a lot better for your brain than watching TV so we're all a step ahead haha